Won Jun Choi¹, Jongmin Yoon², Kyung-Jung Moon¹, Hyunkee Hong¹, Sangmin Kim¹, Seung-Hoon Lee³, Dai Ho Ko³, Jhoon Kim⁴, Dongwon Lee² and GEMS Project Office, (1)National Institute of Environmental Research, Incheon, South Korea, (2)National Institute of Environmental Research, Environmental Satellite Center, Incheon, South Korea, (3)Korea Aerospace Research Institute, Daejeon, Korea, Republic of (South), (4)Yonsei University, Seoul, South Korea